The question really is why do you even bother to type a URL in at all? I have no idea what the point of the URL entry field is, so it'll likely be for a mania link or some such undocumented (two sets of instructions, and the PDF in the game install folder (HINT) don't even mention it!) feature that so far doesn't appear to do much if anything.

If that's the case (you'll possibly find info on this is you SEARCH THE FORUM!), you'll still have to form the full website type URL correctly.

It's all just so much easier if you ignore the URL field altogether, and just type the car name into the dark slot above "Select URL". The car's painted 2D skin will still be saved into the proper folder structure, it'll still appear in a garage slot, and you'll still be able to use it in the game.

I am having the same issues, however, (after changing the cars name) I change the design, I hit that "Save as" button the screen freezes, turns black, and I am left with a little blue message saying my driver crashed.